1. Field
The present invention relates generally to an electronic device, and more particularly to a semiconductor memory device and a program method thereof.
2. Discussion of Related Art
A semiconductor memory device is an electronic data storage device that exploits the electronic properties of semiconductor materials such as silicon (Si), germanium (Ge), and a gallium arsenide (GaAs), indium phosphide (InP). A semiconductor memory device is divided into a volatile memory device and a nonvolatile memory device.
The volatile memory device requires power supply to maintain the stored data. The volatile memory device includes a static RAM (SRAM), a Dynamic RAM (DRAM), a Synchronous DRAM (SDRAM), and the like. By contrast, the nonvolatile memory device maintains data stored in the device even in absence of power supply. The nonvolatile memory device includes a Read Only Memory (ROM), a Programmable ROM (PROM), an Electrically Programmable ROM (EPROM), an Electrically Erasable and Programmable ROM (EEPROM), a flash memory, a Phase-change RAM (PRAM), a Magnetic RAM (MRAM), a Resistive RAM (RRAM), a Ferroelectric RAM (FRAM), and the like. The flash memory is generally divided into a NOR type and a NAND type.
The semiconductor memory device stores information in a memory cell array which includes a plurality of memory cells. For example, the memory cell array includes a plurality of cell strings. An interval between each of the plurality of memory cells and an interval between each of the plurality of cell strings continue to decrease to highly integrate the semiconductor memory device, thereby increasing disturbance between the plurality of memory cells and between the plurality of cell strings. Because the disturbance may deteriorate the reliability of the semiconductor memory device, various methods to reduce the disturbance are being developed.